Capacitor with charge time reducing additives and work function modifiers

Abstract

A capacitor, and method for making the capacitor, is provided with improved charging characteristics. The capacitor has an anode, a cathode comprising a conductive polymer layer and a work function modifier layer adjacent the conductive polymer layer and a dielectric layer between the anode and the cathode.

The invention claimed is: 
     
       1. A method for forming a capacitor comprising:
 forming an anode; 
 forming a dielectric on said anode; and 
 forming a cathode on said anode comprising: 
 forming a conductive polymer layer; and 
 forming a work function modifier layer in a location to be adjacent said conductive polymer layer. 
 
     
     
       2. The method for forming a capacitor of  claim 1  wherein said work function modifier layer is formed between said dielectric layer and said conductive polymer layer wherein said work function modifier layer is formed between said conductive polymer layer and an adjacent conductive polymer layer. 
     
     
       3. The method for forming a capacitor of  claim 1  wherein said capacitor has a CV of at least 400 μFV. 
     
     
       4. The method for forming a capacitor of  claim 1  further comprising measuring a charge time wherein said charge time is no more than 1.5 times a theoretical charge time. 
     
     
       5. The method for forming a capacitor of  claim 4  wherein said charge time is no more than 1.2 times said theoretical charge time. 
     
     
       6. The method for forming a capacitor of  claim 4  wherein said charge time is no more than 1 times said theoretical charge time. 
     
     
       7. The method for forming a capacitor of  claim 1  wherein said conductive polymer layer comprises a polyanion. 
     
     
       8. The method for forming a capacitor of  claim 7  wherein said polyanion is polystyrene sulfonic acid. 
     
     
       9. The method for forming a capacitor of  claim 1  wherein said work function modifier layer comprises a work force modifier reducing a work function of said conductive polymer layer. 
     
     
       10. The method for forming a capacitor of  claim 9  wherein said work function modifier layer reduces said work function by at least 0.1 eV to no more than 1 eV. 
     
     
       11. The method for forming a capacitor of  claim 9  wherein said work function modifier layer reduces said work function to no more than 0.5 eV. 
     
     
       12. The method for forming a capacitor of  claim 9  wherein said work function modifier layer has a particle size of at least 10 nm to no more than 100 nm. 
     
     
       13. The method for forming a capacitor of  claim 9  wherein said work function modifier layer has a particle size of at least 20 nm to no more than 40 nm. 
     
     
       14. The method for forming a capacitor of  claim 9  wherein said work function modifier layer is an inorganic oxide. 
     
     
       15. The method for forming a capacitor of  claim 14  wherein said inorganic oxide is selected from zinc oxides, cerium oxides, indium oxides and manganese oxides. 
     
     
       16. The method for forming a capacitor of  claim 9  wherein said work function modifier layer is an organometallic compound. 
     
     
       17. The method for forming a capacitor of  claim 16  wherein the organometallic compound is an organotitanate. 
     
     
       18. The method for forming a capacitor of  claim 17  wherein said organotitanates is selected from the group consisting of di-alkoxy acyl titanate, tri-alkoxy acyl titanate, alkoxy triacyl titantate, alkoxy titantate, neoalkoxy titanate with titanium IV 2,2(bis 2-propenolatomethyl) butanolato, tris neodecanoato-O; titanium IV 2,2(bis 2-propenolatomethyl) butanolato, iris(dodecyl)benzenesulfonato-O; titanium IV 2,2(bis 2-propenolatomethyl) butanolato, tris(dioctyl)phosphato-O; titanium IV 2,2(bis 2-propenolatomethyl) tris(dioctyl)pyrophosphatobutanolato-O; titanium IV 2,2(bis 2-propenolatomethyl) butanolato, tris(2-ethylenediamino)ethylato; and titanium IV 2,2(bis 2-propenolatomethyl) butanolato, tris(3-amino)phenylato and derivatives thereof. 
     
     
       19. The method for forming a capacitor of  claim 18  wherein said alkoxy titanate is a neoalkoxy titanate. 
     
     
       20. The method for forming a capacitor of  claim 9  where said work function modifier layer is an organic compound with reactive functional groups. 
     
     
       21. The method for forming a capacitor of  claim 20  wherein at least one functional group of said functional groups is epoxy. 
     
     
       22. The method for forming a capacitor of  claim 20  wherein said work function modifier layer is selected from the group consisting of cycloaliphatic epoxy resin, ethylene glycol diglycidyl ether, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, aliphatic epoxy resin, Glycidylamine epoxy resin, ethylene glycol diglycidyl ether (EGDGE), propylene glycol diglycidyl ether (PGDGE), 1,4-butanediol diglycidyl ether (BDDGE), pentylene glycol diglycidyl ether, hexylene glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, resorcinol glycidyl ether, glycerol diglycidyl ether (GDGE), glycerol polyglycidyl ethers, diglycerol polyglycidyl ethers, trimethylolpropane polyglycidyl ethers, sorbitol diglycidyl ether (Sorbitol-DGE), sorbitol polyglycidyl ethers, polyethylene glycol diglycidyl ether (PEGDGE), polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, di(2,3-epoxypropyl)ether, 1,3-butadiene diepoxide, 1,5-hexadiene diepoxide, 1,2,7,8-diepoxyoctane, 1,2,5,6-diepoxycyclooctane, 4-vinyl cyclohexene diepoxide, bisphenol A diglycidyl ether, maleimide-epoxy compounds, and derivatives thereof. 
     
     
       23. The method for forming a capacitor of  claim 9  wherein said work function modifier layer is a polycationic compound. 
     
     
       24. The method for forming a capacitor of  claim 23  wherein said work function modifier layer is selected from the group consisting of amidinium, phosphonium, quaternary ammonium, guanadinium, anilinium, thiouronium, carbenium, pyridinium, imidazolium, sulfonium, diazonium and derivatives thereof. 
     
     
       25. The method for forming a capacitor of  claim 9  wherein said work function modifier layer is an ionic liquid. 
     
     
       26. The method for forming a capacitor of  claim 25  wherein said work function modifier layer is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         1-ethyl-3-methylimidazolium tetrafluoroborate and derivatives thereof.